Only time will tell how Grandy's pop translates to Citi

Statistical projection systems predict outfielder to have lowest homer total since '06

By Anthony DiComo / MLB.com

NEW YORK -- It was not until Curtis Granderson's fourth full season that he cracked 30 home runs for the first time. Even in his (somewhat injury-shortened) debut year at Yankee Stadium, Granderson hit only 24 homers. One of the first things he said after officially signing with the Mets was that he does not consider himself a home run hitter.

Yet the Mets are paying Granderson $60 million primarily to whack balls over the fence. It's a gamble; to many around the game, the question seems to be not whether Granderson will endure a power drop-off at Citi Field, but how large that decrease will be.

"I've never gone up to a situation trying to do anything out there except for get a good pitch and try to hit it and do some damage with it," Granderson said shortly after the ink dried on his four-year contract. "In Citi Field, some of that damage might be a little different than others. But as long as you're going ahead and putting the bat on the ball and doing the things you know you can, you have a chance to score some runs."

How many runs is what Mets fans want to know. According to the website HitTracker Online, one out of every five homers Granderson hit from 2001-13 would not have gone out of Citi Field. Though Citi's dimensions are not what they once were, and though the park has never been as tough on left-handed hitters as on -- ahem, Jason Bay -- righties, Granderson is coming directly from one of the league's foremost launching pads.

"There are 30 ballparks, and all of them are different in their own ways," was how Granderson put it. "They all have pros and cons, no matter what they happen to be."

That's a lesson Granderson learned after leaving Comerica Park for Yankee Stadium in 2010, and quickly realizing the difference between the two ballparks. After averaging 23.5 homers annually in his four full seasons with the Tigers, Granderson set career highs in home-run-to-fly-ball ratio in each of his first three years as a Yankee. His isolated power -- a metric that measures exactly what it sounds like it should -- soared to new heights. And Granderson translated that into back-to-back 40-homer seasons in 2011-12.

Along the way, Granderson said, his swing evolved. So it can evolve back if necessary.

"It's not going to be a revert; it's going to be another modification," Granderson said. "My swing, from my first day in 2004 to where I sit right now, has been different and evolving for different reasons -- comfort, consistency, flexibility, all those things. We'll continue to change those things as we start this season and as my career goes on."

In predicting Granderson's future home run output, there is also the far simpler matter of aging. He will be 33 in March, an age when most players -- power hitters or speedsters, big stadiums or small -- tend to lose skill and become increasingly susceptible to injury. While not impossible, the notion that the 33-year-old Granderson will be identical to the 30-year-old Granderson is an overly hopeful one.

ZIPS and Oliver, two statistical projection systems that adjust for aging, predict Granderson to hit 20 and 19 home runs, respectively. Either would represent his lowest homer total since 2006, not including his injury-plagued 2013 season.

Yet that is not to say Granderson will be unsuccessful in his new digs. He gives the Mets a legitimate left-handed power source to protect David Wright and -- if things break their way -- supplement Ike Davis or Lucas Duda in the lineup. Recall that Wright ranked second on the Mets with 18 homers last year; even if Granderson's power declines drastically, he should still rank among the team leaders in homers.

"We understand that Citi Field is not Yankee Stadium, and that will have some impact on his statistical record," said Mets general manager Sandy Alderson, whose staff explored the issue on a basic level before signing Granderson. "But everything's relative, and we're looking for excellence. We're not looking for any particular numbers."

In time, Granderson's home run tallies will come regardless. It is only then that the Mets will truly understand what type of player they have signed -- a home run hitter still in his prime, or the victim of age and ballpark factors beyond his control.

Anthony DiComo is a reporter for MLB.com. Follow him on Twitter @AnthonyDicomo. This story was not subject to the approval of Major League Baseball or its clubs.